Solar cells are created by forming a pn junction in a semiconductor workpiece. Light energy impinging the solar cell excites electrons in the solar cell, leading to the creation of current flow. Various types of solar cells exist, including back contact solar cells, in which all of the circuit contacts are on the back surface. This may improve efficiency since the entirety of the front surface is available for receiving light energy.
However, more processing may be used to create the desired dopant pattern on the back surface of a back contact solar cell. In one embodiment, the pattern is referred to as interdigitated, where the emitter and back surface fields are complementary patterns that comprise the entirety of the back surface. For improved efficiency, it may be beneficial for the emitter and back surface fields to be aligned where one another such that gaps do not exist between them.
However, precise alignment often leads to the use of high precision equipment or multiple processes, which leads to decreased throughput, resulting in increased cost.
Therefore, it would be advantageous if there were a method of forming an interdigitated solar cell that was inexpensive and reduced the necessity for high precision processing.